This invention relates to novel N-(heterocyclicaminocarbonyl)arysulfonamides in which at least one of the acyclic nitrogens thereof is substituted by lower alkyl, or in some cases by methoxy. The compounds of this invention and their agriculturally suitable salts, are useful as agricultural chemicals, such as plant growth regulants and herbicides.
Netherlands Pat. No. 121,788, published Sept. 15, 1966, discloses the preparation of compounds of the following Formula and their use as general or selective herbicides, ##STR1## wherein
R.sub.1 and R.sub.2 may independently be alkyl of 1-4 carbon atoms; and
R.sub.3 and R.sub.4 may independently be hydrogen, chlorine or alkyl of 1-4 carbon atoms.
U.S. Pat. No. 3,637,366 discloses compounds having the formula: ##STR2## wherein
R.sub.1 is hydrogen or lower saturated aliphatic acyl and
R.sub.2 is hydrogen, 2-pyrimidinyl, pyridyl, amidino, acetyl or carbamoyl. The disclosed compounds are said to provide control of crabgrass, cress, endive, clover and Poa annua.
French Pat. No. 1,468,747 discloses the following para-substituted phenylsulfonamides as being useful as antidiabetic agents: ##STR3## wherein R=H, halogen, CF.sub.3 or alkyl.
Compounds of the following formula, and their use as antidiabetic agents, are reported in J. Drug Res. 6, 123 (1974). ##STR4## wherein R is pyridyl.
Logemann et al. Chem Ab., 53, 18052 g (1959), disclose a number of sulfonamides, including uracil derivatives and those having the formula: ##STR5## wherein R is butyl, phenyl or ##STR6## and R.sub.1 is hydrogen or methyl. When tested for hypoglycemic effect in rats (oral doses of 25 mg/100 g), the compounds in which R is butyl and phenyl were most potent. The others were of low potency or inactive.
Wojciechowski, J. Acta. Polon. Pharm 19, p. 121-5 (1962) [Chem. Ab., 59 1633 e] describes the synthesis of N-[(2,6-dimethoxypyrimidin-4-yl)aminocarbonyl]-4-methyl-benzenesulfonamide : ##STR7## Based upon similarity to a known compound, the author predicted hypoglycemic activity for the foregoing compound.
Substituted-pyrimidinyl sulfonylureas of the following formula, which are also para-substituted on the phenyl ring, are disclosed in Farmco Ed. Sci., 12, 586 (1957) [Chem. Ab., 53, 18052 g (1959)]: ##STR8## wherein R=H or CH.sub.3.
The presence of undesired vegetation causes substantial damage to useful crops, especially agricultural products that satisfy man's basic food and fiber needs, such as cotton, rice, corn, wheat, and the like. The current population explosion and concomitant world food and fiber shortage demand improvements in the efficiency of producing these crops. Preventing or minimizing loss of a portion of such valuable crops by killing, or inhibiting the growth of undesired vegetation is one way of improving this efficiency.
A wide variety of materials useful for killing or inhibiting (controlling) the growth of undesired vegetation is available; such materials are commonly referred to as herbicides. However, the need still exists for effective herbicides that destroy or control weeds while not significantly damaging useful crops. Some weeds (nutsedge is a particular example) are very difficult to control; many of the herbicides that are used to control nutsedge are so nonselective that they cause damage to the crops themselves.